1. Field of the Invention
The invention relates to liquid crystal display panels, and in particular to alignment protrusion design thereof.
2. Description of the Related Art
Multi-domain vertical alignment (MVA) is popular for use in wide-viewing angle liquid crystal display panels, in which alignment protrusions are formed on a substrate, such that the liquid crystal molecules are perpendicular to the alignment protrusions. The liquid crystal molecules can function as dual-domain, quad-domain, or multi-domain by designing the alignment protrusion pattern. Because the liquid crystal molecules do not align in a single direction, normal images are viewable from different angles. Even in large liquid panels, the viewing angle can be modified to almost 180°.
Conventional alignment protrusions comprise general photoresist such as positive type or negative photoresist. Because the alignment protrusions are formed of transparent photoresist materials, light leakage occurs in dark conditions. As shown in FIG. 1, a conventional liquid crystal panel 1 comprises color filter substrate 11, array substrate 13, and liquid crystal layer 17 disposed therebetween. The color filter substrate 11 is a multi-layered structure including transparent conductive layer 11a, color filters 11b, and transparent substrate 11c underlying the transparent alignment protrusion 10. The array substrate 13 is a multi-layered structure including transparent conductive layer 13a, passivation layer 13b, dielectric layer 13c, and transparent substrate 13d, wherein the transparent conductive layer 13a has slits 15 corresponding to the alignment protrusion 10. The liquid crystal molecules 17a near the alignment protrusion 10, unlike the liquid crystal molecules 17b in other regions, are not perpendicular to the substrate in dark conditions. When incident light passes through the liquid crystal layer 17, the phase difference causes light leakage as shown in light leakage curve 19, where a longitudinal axis shows light leakage strength, and the transverse axis corresponds to the position of the protrusion 10 of the color filter substrate 11.